The invention relates to a device for inductive transmission of electric power.
A similar device, which is known for example from WO 92/17929, serves for transmission of electrical power to at least one mobile pick-up without a mechanical or electrical contact. It comprises a primary and a secondary part, which are electromagnetically coupled similarly to the transformer principle. The primary part consists of input electronics and a conductor loop deployed along a path. One or more pick-ups and the associated electronic components of the pick-up form a secondary part. In contrast to a transformer, when a primary and a secondary part are coupled together as closely as possible, a loosely coupled system is created. This system can be realized with a relatively high operating frequency in the kiloherz range, which makes it possible to create a bridge even between large air gaps of up to several centimeters. In this case, the operating frequency is determined on the secondary side as a resonance frequency, which is formed with a parallel connection of a condenser to a pick-up coil.
Among the advantages of this type of power transmission are in particular freedom from the wear and tear maintenance, as well as the safety of the contact and a degree of availability. Typical applications are in the area of material transport systems for the manufacturing technology, but also for personal transport systems such as elevators and electrically driven buses. Many of these applications require a connection for communication between a central control station and the mobile pick-up, in particular for controlling the pick-up with remote control. Moreover, in a system that has a plurality of pick-ups it can be also desirable for the pick-ups to be able to communicate with each other, for instance in order to coordinate independently their movements and to prevent collisions. Based on the existing state of art, similar communication is normally achieved in the form of radio communication.